Under the Microscope Humans are symbolic animals. Symbols make culture possible and its transmission from one generation to the next.
Use of symbols also allows us to learn without the need for direct experience of the subject matter. As young children we learn to think symbolically, ie that one thing can represent another, but we find it difficult initially to get the hang of it. Studies of how we acquire a facility to use symbols shed light into the heart of our humanity. They also have important consequences for interpretation of the use of life-like dolls when investigating suspected cases of child abuse. Recent research in this area is reviewed by Judy S DeLoach in Scientific American, August 2005.
Children make a significant jump in their capacity for symbolic understanding between the ages of two-and-a-half and three years. DeLoache describes work that illustrates this. She built a miniature model of a living room, complete with armchair, couch, cabinet etc. The model was an accurate copy of an adjoining full-size living room. The children watched as DeLoache hid a miniature toy in the model room. A full-size toy was hidden in the corresponding place in the big living room, but the children didn't see this being done. The object of the study was to see if the children could use their memory of the location of the miniature toy in the model room to find the big toy in the big room.
Three-year-old children had no difficulty in locating the big toy behind the couch in the full-size living room, but two-and-a-half-year-old kids had no idea where to look despite knowing where the toy was hidden in the model room. They didn't appreciate the relationship between the model and the room.
Probably the most familiar example of a symbol is a picture. It is not the object it represents, but it closely resembles the object. DeLoache and her colleagues have investigated how children interpret and deal with pictures from the ages of a few months to several years old.
When nine month old, infants are presented with realistic colour pictures of objects they almost invariably reach out to rub or manipulate the illustrated object. The confusion is conceptual, not perceptual. When offered a choice between a picture and the real thing, infants choose the real thing. But they still do not understand how pictures differ from the real thing.
Therefore they explore - for example a nine-month-old baby will try to put his/her foot into a photograph of a shoe.
By the age of 18 months most babies have learned the difference between pictures and the objects they represent. At this stage they point at pictures and name the objects, or ask to be told the name. However, the nature of pictures is not completely understood for several years and up to the age of four, children think, for example, that if you turn a picture of a bowl of cereal upside down the cereal will fall out of the bowl. Pictures are not the only source of confusion for very young children and one-and-a-half to two-and-a-half-year-old children will often try to sit on tiny scale model chairs. (See www.faculty.virginia.edu/childstudycenter/home.html)
These same-aged children were also studied in another experiment where they were shown an ordinary sized object, eg a doll, in an ordinary sized tent. They were then told that a magic machine would shrink the tent and its contents when they left for a short period. When they returned they saw a small tent where the big one had been. The children were asked to look for the doll and they immediately began to look in the model tent. Unlike in the experiment described at the start of this article, they had no dual representation to handle. The small tent was the same as the big tent. This shows that the need to think of an object in two ways at once is the core of the child's inability to understand symbols.
Investigations of suspected abuse of young children is difficult because the children are difficult to interview. It has therefore been the practice to use anatomically detailed dolls in the belief that the child will find it easier to describe what happened using the doll. This assumes that the child can think of the object both as a doll and as a representation of himself/herself.
This assumption is not safe. In one study, pre-school children were asked what they remembered after visits to their paediatrician, some of which had included a genital check. Sometimes anatomically detailed dolls were used when questioning the children. Generally the children's reports were more accurate when questioned without the "assistance" of the doll. DeLoache has also confirmed this result in other studies. The use of dolls when investigating children under the age of five has to be viewed with some suspicion.
There are also implications for educational practices. Pre-school teachers all over the world use objects such as blocks to help children to appreciate abstract mathematical principles. But if the children do not grasp the symbolism their use could hinder more than help. Research carried out by DeLoache on teaching maths to six- and seven-year-olds found that using symbols to teach subtraction took three times longer to get the point across than the simple old fashioned method of using pencil and paper.
• William Reville is associate professor of biochemistry and public awareness of science officer at UCC - http://understandingscience.ucc.ie